<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>

    <script>
        // 4.声明一个函数, 传入一个对象作为形参，返回该对象中所有属性名拼接起来的字符串
        // 例如  { name: "", age: "", data: "" }=> name + age + data

        function nameJoint(obj){
            let nameVlaue = ''
            for (const k in obj) {
                nameVlaue = nameVlaue + k
            }

            return nameVlaue
        }


        console.log(nameJoint({ name: "", age: "", data: "" }));

    </script>

</body>

</html>